Voltage-multiplying DC converter based on charge pump capacitor

Abstract

The invention relates to a voltage-multiplying DC converter based on a charge pump capacitor. The voltage-multiplying DC converter comprises an input power supply, a main switch loop, a freewheel diode, an output capacitor and a load, wherein the input power supply is connected with the input end of the main switch loop; and the freewheel diode is connected with the output end of the main switch loop after serially connecting the output capacitor. The main switch loop includes an input diode, a first inductor, a second inductor, a charge pump capacitor, a first main switch and a second switch, wherein one end of the first main switch is respectively connected with the negative electrode of the input power supply and the output capacitor, and the other end is respectively connected with the first inductor, the charge pump capacitor and the second main switch; the first inductor is respectively connected with the positive electrode of the input power supply and the anode of the input diode; the charge pump capacitor is respectively connected with the cathode of the input diode and the second inductor; and the second main switch is respectively connected with the second inductor and the freewheel diode. In comparison with the prior art, the voltage-multiplying DC converter provided by the invention has the advantages of improved voltage gain, less conduction loss, low cost, simple circuit structure and so on.

Description

technical field [0001] The invention relates to a direct current converter, in particular to a voltage doubling type direct current converter based on a charge pump capacitor. Background technique [0002] With the rapid development of new energy in recent years, distributed power generation systems using green energy as primary power sources have also attracted more and more attention. However, due to the low input value of photovoltaic power generation and fuel cell power generation systems, a step-up DC converter is required at the front end of the system to increase the low voltage emitted by the new energy. However, how to design a converter with a higher boost ratio at low cost and high efficiency has become a very important issue. Traditional DC boost converters such as figure 1 As shown, the prior art mainly has the following disadvantages: [0003] 1. In order to achieve high gain, for traditional DC boost converters, the method of increasing the switching duty c...

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Problems solved by technology

However, this method will increase the conduction loss due to the long conduction time required by the switch, increase the input current ripple, and reduce the conversion efficiency of the circuit, and the switching frequency will also be limited in many aspects in practical applications.

[0004] 2. The structure of the multi-stage connection method makes the topology of the main circuit more complex, thus increasing the manufacturing cost. On the other hand, the multi-stage connection also increases the difficulty of control and reduces the circuit efficiency.

[0005] 3. The use of transformers and coupled inductors will easily increase the overall volume. In addition, in order to obtain a suitable gain, the design of the number of turns and the iron core is also difficult.

[0006] 4. The leakage inductance and parasitic capacitance of transformers and coupled inductors may cause high-frequency oscillations, which can easily cause peak pulses in the switching voltage and easily generate electromagnetic interference

[0007] 5. In order to solve the above problems, a buffer circuit needs to be added, which increases the cost and complicates the circuit

[0008] 6. The voltage stress at both ends of the switch is always equal to the output voltage, which limits the selection of switching devices

[0009] In view of the above reasons, traditional DC boost converters are difficult to meet the requirements of simplicity, high efficiency, small size, low noise and low cost

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